Merge record into ActiveRecord Relation

问题

I pull a record as:

def self.imp_broadcast_preview!
  Broadcast.where(for_gamers: true).order(:created_at).last
end

And then in my controller I have:

def index
  @conversations = Conversation.where(gamer: @gamer)
  @conversations << Broadcast.imp_broadcast_preview!
end

The above code works properly in Rails 4.2 and merges the last broadcast message in the conversations. I just updated my codebase to Rails 5.2 and now I am getting an error:

NoMethodError (undefined method `<<' for #<Conversation::ActiveRecord_Relation:0x00007fd2541baca0>)

I tried using merge instead but that throws an error as well since broadcast is not an activerecord relation

回答1:

That functionality got removed in rails 5.0, you can check https://github.com/rails/rails/issues/25906. There you'll find why it was removed, and the link to the commit that removed that functionality.

To make your code work, what you should do is to convert to an Array your first result, that way << will work:

def index
  @conversations = Conversation.where(gamer: @gamer).to_a
  @conversations << Broadcast.imp_broadcast_preview!
end

来源：https://stackoverflow.com/questions/53891347/merge-record-into-activerecord-relation